The free radical forms of adriamycin, daunorubicin, adriamycinol, and daunorubicinol show interconversion to a second asymmetric form which indicates a change in physical state. Hyperfine structure indicates electron density on the A and B Rings. Kinetics of free radical conversion suggest the free radical is obligatory to glycosidic cleavage. Liver carbonyl reductases show substrate and product stereospecificity. Actinomycin D and its analogs show free radical spectra when reduced by chemical means.